Elastomer-Protected Anode and Lithium Battery

Abstract

An anode layer for a lithium battery, said anode layer comprising (a) 50% to 95% by weight of multiple anode active material particles; (b) 0.01% to 30% by weight of a conductive additive; and (c) a high-elasticity polymer having a recoverable tensile strain from 5% to 1,000% and a lithium ion conductivity no less than 10−6 S/cm, wherein the high-elasticity polymer comprises (i) an elastomer or rubber and (ii) a lithium ion-conducting phase comprising plastic crystal and/or organic plasticizer domains containing an optional lithium salt therein, wherein the elastomer or rubber and the lithium ion-conducting phase, separately or in combination, form a network of lithium ion-conducting pathways; the conductive additive forms a network of electron-conducing pathways that are in electrical contact with the anode particles; and the high-elasticity polymer bonds, encapsulates, embraces, or coats on the surfaces of the anode particles and the conductive additive.

We claim: 
     
         1 . An anode active material layer for a lithium battery, said anode active material layer comprising:
 a) 50% to 95% by weight of multiple anode active material particles;   b) 0.01% to 30% by weight of a conductive additive; and   c) a high-elasticity polymer having a recoverable tensile strain from 5% to 1,000% when measured without an additive or reinforcement in said polymer and a lithium ion conductivity no less than 10 −6  S/cm at room temperature, wherein said high-elasticity polymer comprises (i) an elastomer or rubber and (ii) a lithium ion-conducting phase comprising plastic crystal domains and/or organic plasticizer domains, wherein:
 the elastomer or rubber and the lithium ion-conducting phase, separately or in combination, form a network of lithium ion-conducting pathways; 
 the amount of conductive additive is sufficient to form a network of electron-conducing pathways that are in electrical contact with the anode active material particles; and 
 the high-elasticity polymer bonds, encapsulates, embraces, or coats on the surfaces of the anode active material particles and the conductive additive so as to maintain the structural integrity of the anode electrode, preventing interruption of the electron- and lithium ion-conducting pathways when the anode active material particles repeatedly expand and shrink in volume during battery cycling. 
   
     
     
         2 . The anode active material layer of  claim 1 , wherein the elastomer or rubber is selected from natural polyisoprene, synthetic polyisoprene, polybutadiene, chloroprene rubber, polychloroprene, butyl rubber, butyl acrylic rubber, styrene-butadiene rubber, nitrile rubber, ethylene propylene rubber, ethylene propylene diene rubber, epichlorohydrin rubber, polyacrylic rubber, silicone rubber, polysiloxane, fluorosilicone rubber, perfluoroelastomers, polyether block amides, chlorosulfonated polyethylene, ethylene-vinyl acetate, thermoplastic elastomer, protein resilin, protein elastin, ethylene oxide-epichlorohydrin copolymer, polyurethane, urethane-urea copolymer, poly(phosphazene), a copolymer thereof, a chemically substituted version thereof, a chemical derivative thereof, a sulfonated version thereof, or a combination thereof. 
     
     
         3 . The anode active material layer of  claim 1 , wherein said high-elasticity polymer contains a lithium salt dispersed or dissolved in the elastomer or rubber and/or in the lithium ion-conducting phase. 
     
     
         4 . The anode active material layer of  claim 1 , wherein the high-elasticity polymer comprises from 5% to 95% by weight of plastic crystal domains and/or organic plasticizer domains dispersed in or connected to the elastomer or rubber. 
     
     
         5 . The anode active material layer of  claim 4 , wherein the elastomer or rubber and the plastic crystal or organic plasticizer domain form co-continuous phases exhibiting a lithium-ion conductivity no less than 10 −5  S/cm. 
     
     
         6 . The anode active material layer of  claim 1 , wherein the plastic crystal or organic plasticizer domains comprise a mixture of a lithium salt and an organic plasticizer selected from a fluorinated carbonate, hydrofluoroether, fluorinated vinyl carbonate, fluorinated ester, fluorinated vinyl ester, fluorinated vinyl ether, sulfone, sulfide, nitrile, phosphate, phosphonate, phosphinate, phosphine, phosphine oxide, phosphonic acid, phosphorous acid, phosphite, phosphoric acid, phosphazene compound, sulfate, siloxane, silane, 1,3-dioxolane (DOL), 1,2-dimethoxyethane (DME), tetraethylene glycol dimethylether (TEGDME), poly(ethylene glycol) dimethyl ether (PEGDME), diethylene glycol dibutyl ether (DEGDBE), 2-ethoxyethyl ether (EEE), sulfolane, acetonitrile (AN), acrylonitrile, succino-nitrile, dinitrile, fluoroethylene carbonate (FEC), an ionic liquid solvent, a polymerized version thereof, or a combination thereof. 
     
     
         7 . The anode active material layer of  claim 6 , wherein the polymerized version of the organic plasticizer has a molecular weight less than 10,000 g/mole. 
     
     
         8 . The anode active material layer of  claim 6 , wherein the sulfone or sulfide is selected from vinyl sulfone, allyl sulfone, alkyl vinyl sulfone, aryl vinyl sulfone, vinyl sulfide, a vinyl-containing variant of TrMS, MTrMS, TMS, EMS, MMES, EMES, EMEES, or a combination thereof: 
       
         
           
           
               
               
           
         
       
     
     
         9 . The anode active material layer of  8 , wherein the vinyl sulfone or sulfide is selected from ethyl vinyl sulfide, allyl methyl sulfide, phenyl vinyl sulfide, phenyl vinyl sulfoxide, allyl phenyl sulfone, allyl methyl sulfone, divinyl sulfone, or a combination thereof, wherein the vinyl sulfone does not include methyl ethylene sulfone and ethyl vinyl sulfone. 
     
     
         10 . The anode active material layer of  claim 6 , wherein the nitrile comprises a dinitrile or is selected from AND, GLN, SEN, succino-nitrile, or a combination thereof: 
       
         
           
           
               
               
           
         
       
     
     
         11 . The anode active material layer of  claim 6 , wherein the phosphate is selected from allyl-type, vinyl-type, styrenic-type and (meth)acrylic-type monomers bearing a phosphonate moiety. 
     
     
         12 . The anode active material layer of  claim 6 , wherein the phosphate, phosphonate, phosphonic acid, phosphazene, or phosphite is selected from TMP, TEP, TFP, TDP, DPOF, DMMP, DMNIEM P, tris(trimethylsilyl)phosphite (TTSPi), alkyl phosphate, triallyl phosphate (TAP), a combination thereof, wherein TMP, TEP, TFP, TDP, DPOF, DMMP, DMMEMP, and phosphazene have the following chemical formulae: 
       
         
           
           
               
               
           
         
         wherein R═H, NH 2 , or C 1 -C 6  alkyl. 
       
     
     
         13 . The anode active material layer of  claim 6 , wherein the siloxane or silane is selected from alkylsiloxane (Si—O), alkyylsilane (Si—C), liquid oligomeric silaxane (—Si—O—Si—), or a combination thereof. 
     
     
         14 . The anode active material layer of  claim 3 , wherein said lithium salt is selected from lithium perchlorate (LiClO 4 ), lithium nitrate (LiNO 3 ), lithium hexafluorophosphate (LiPF 6 ), lithium borofluoride (LiBF 4 ), lithium hexafluoroarsenide (LiAsF 6 ), lithium trifluoro-metasulfonate (LiCF 3 SO 3 ), bis-trifluoromethyl sulfonylimide lithium (LiN(CF 3 SO 2 ) 2 ), lithium bis(oxalato)borate (LiBOB), lithium oxalyldifluoroborate (LiBF 2 C 2 O 4 ), lithium oxalyldifluoroborate (LiBF 2 C 2 O 4 ), lithium nitrate (LiNO 3 ), Li-Fluoroalkyl-Phosphates (LiPF 3 (CF 2 CF 3 ) 3 ), lithium bisperfluoro-ethysulfonylimide (LiBETI), lithium bis(trifluoromethanesulphonyl)imide, lithium bis(fluorosulphonyl)imide, lithium trifluoromethanesulfonimide (LiTFSI), an ionic liquid lithium salt, Li 2 CO 3 , Li 2 O, Li 2 C 2 O 4 , LiOH, LiX, ROCO 2 Li, HCOLi, ROLi, (ROCO 2 Li) 2 , (CH 2 OCO 2 Li) 2 , Li 2 S, Li x SO y , wherein X=F, Cl, I, or Br, R=a hydrocarbon group, x=0-1, y=1-4, or a combination thereof. 
     
     
         15 . The anode active material layer of  claim 2 , wherein said chemically substituted version comprises a H atom being substituted with an alkali cation selected from Li + , Na + , K + , NH 4   + , or a combination thereof. 
     
     
         16 . The anode active material layer of  claim 1 , wherein the conductive additive comprises a graphite, graphene, or carbon material. 
     
     
         17 . The anode active material layer of  claim 16 , wherein said graphite, graphene, or carbon material is selected from polymeric carbon, amorphous carbon, chemical vapor deposition carbon, coal tar pitch, petroleum pitch, meso-phase pitch, carbon black, coke, acetylene black, activated carbon, graphite particles, carbon particles, meso-phase microbeads, carbon or graphite fibers, carbon nanotubes, carbon nano-fibers, graphitic nano-fibers, graphene sheets, or a combination thereof and said graphite, graphene, or carbon material forms a 3D network of electron-conducting pathways that are in electronic contacts with said anode material particles. 
     
     
         18 . The anode active material layer of  claim 1 , wherein said anode active material is selected from the group consisting of: (a) silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), phosphorus (P), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), and cadmium (Cd); (b) alloys or intermetallic compounds of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Ni, Co, or Cd with other elements; (c) oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of Si, Ge, Sn, Pb, Sb, Bi, Zn, Al, Ti, Fe, Ni, Co, V, or Cd, and their mixtures, composites, or lithium-containing composites; (d) salts and hydroxides of Sn; (e) lithium titanate, lithium manganate, lithium aluminate, lithium titanium niobium oxide, lithium-containing titanium oxide, lithium transition metal oxide, ZnCo 2 O 4 ; (f) carbon or graphite particles (g) prelithiated versions thereof; (h) particles of lithium or lithium alloy; and (i) combinations thereof. 
     
     
         19 . The anode active material layer of  claim 1 , wherein said anode active material contains a prelithiated Si, prelithiated Ge, prelithiated Sn, prelithiated SnO x , prelithiated SiO x , prelithiated iron oxide, prelithiated V 2 O 5 , prelithiated V 3 O 8 , prelithiated Co 3 O 4 , prelithiated Ni 3 O 4 , or a combination thereof, wherein x=1 to 2, wherein said anode active material is lithiated to contain from 0.1% to 54.7% by weight of lithium. 
     
     
         20 . The anode active material layer of  claim 1 , wherein said anode active material particles are porous. 
     
     
         21 . The anode active material layer of  claim 1 , wherein one or a plurality of said particles is coated with a layer of carbon or graphene disposed between said one or said plurality of particles and said high-elasticity polymer. 
     
     
         22 . The anode active material layer of  claim 1 , wherein said high-elasticity polymer comprises a blend, copolymer, crosslinked network, or interpenetrating network of the elastomer or rubber and an electron-conducting polymer comprising chains of a conjugated polymer selected from polyacetylene, polythiophene, poly(3-alkylthiophenes), polypyrrole, polyaniline, poly(isothianaphthene), poly(3,4-ethylenedioxythiophene), alkoxy-substituted poly(p-phenylene vinylene), poly(2,5-bis(cholestanoxy) phenylene vinylene), poly(p-phenylene vinylene), poly(2,5-dialkoxy) paraphenylene vinylene, poly[(1,4-phenylene-1,2-diphenylvinylene)], poly(3′,7′-dimethyloctyloxy phenylene vinylene), polyparaphenylene, polyparaphenylene, polyparaphenylene sulphide, polyheptadiyne, poly(3-hexylthiophene), poly(3-octylthiophene), poly(3-cyclohexylthiophene), poly(3-methyl-4-cyclohexylthiophene), poly(2,5-dialkoxy-1,4-phenyleneethynylene), poly(2-decyloxy-1,4-phenylene), poly(9,9-dioctylfluorene), polyquinoline, a derivative thereof, a copolymer thereof, a sulfonated version thereof, or a combination thereof. 
     
     
         23 . The anode active material layer of  claim 1 , wherein the elastomer or rubber forms a mixture or blend with a lithium ion-conducting polymer selected from poly(ethylene oxide), polypropylene oxide, polyoxymethylene, polyvinylene carbonate, polypropylene carbonate, poly(ethylene glycol), poly(acrylonitrile), poly(methyl methacrylate), poly(vinylidene fluoride), poly bis-methoxy ethoxyethoxide-phosphazenex, polyvinyl chloride, poly(alkylsiloxane), poly(vinylidene fluoride)-hexafluoropropylene, cyanoethyl poly(vinyl alcohol), a pentaerythritol tetraacrylate-based polymer, an aliphatic polycarbonate, a single Li-ion conducting solid polymer with a carboxylate anion, a sulfonylimide anion, or sulfonate anion, poly(ethylene glycol) diacrylate, poly(ethylene glycol) methyl ether acrylate, polyacrylamide, a polyionic liquid, polymerized 1,3-dioxolane, polyepoxide ether, polysiloxane, poly(dimethyl siloxane), poly(alkyl siloxane), poly(acrylonitrile-butadiene), polynorbornene, poly(hydroxyl styrene), poly(ether ether ketone), polypeptoid, poly(ethylene-maleic anhydride), polycaprolactone, poly(trimethylene carbonate), chains of ethylene glycol phenyl ether acrylate) (PEGPEA) or ethoxylated trimethyl propyl triacrylate (ETPTA), poly(phosphate), poly(phosphonate), poly(phosphinate), poly(phosphine), poly(phosphine oxide)_poly(phosphonic acid), poly(phosphorous acid), poly(phosphite), poly(phoslphoric acid), poly(phosphazene), a chemical derivative thereof, a copolymer thereof, a sulfonated derivative thereof, or a combination thereof. 
     
     
         24 . The anode active material layer of  claim 1 , wherein the anode active material layer contains therein from 10% to 70% by volume of pores. 
     
     
         25 . A lithium battery comprising the anode of  claim 1 , a cathode, and an electrolyte in ionic contact with said anode and said cathode. 
     
     
         26 . The lithium battery of  claim 25 , further including an ion-conducting separator. 
     
     
         27 . A method of producing the anode active layer of  claim 1 , said method comprising:
 (a) dispersing multiple primary particles of an anode active material, a conductive additive, and a resin binder in a liquid medium to form a slurry;   (b) forming the slurry onto at least a surface of an anode current collector and removing the liquid medium to form at least an anode layer bonded to the anode current collector, wherein the anode layer is porous containing pores therein;   (c) preparing a reactive liquid solution comprising (i) a monomer with an initiator or a cross-linkable oligomer, or a polymer with a cross-linking agent and (ii) a desired amount of an organic plasticizer or plastic crystal precursor, and impregnating the reactive liquid solution into pores of the porous anode layer; and   (d) polymerizing the monomer and/or cross-linking the oligomer or polymer to form a high-elasticity polymer comprising an elastomer/rubber and a lithium ion-conducting phase, wherein the high-elasticity polymer embraces the primary particles of the anode active material and the conductive additive to form the anode active layer.   
     
     
         28 . A method of producing the anode active layer of  claim 1 , said method comprising:
 a) dispersing multiple primary particles of an anode active material, a conductive additive, and a resin binder in a liquid medium to form a slurry;   b) forming the slurry onto at least a surface of an anode current collector and removing the liquid medium to form at least an anode layer bonded to the anode current collector, wherein the anode layer is porous containing pores therein;   c) preparing a liquid solution comprising a thermoplastic elastomer and an organic plasticizer dissolved or dispersed in a liquid solvent, and impregnating the liquid solution into pores of the porous anode layer; and   d) removing the liquid solvent to precipitate out a high-elasticity polymer comprising the thermoplastic elastomer and domains of plastic crystal or organic plasticizer, wherein the high-elasticity polymer embraces the primary particles of the anode active material and the conductive additive to form the anode active layer.   
     
     
         29 . A method of producing the anode active layer of  claim 1 , said method comprising:
 A) dispersing multiple primary particles of an anode active material and a conductive additive in a reactive liquid solution to form a slurry, wherein the reactive liquid solution comprises a plasticizer or plastic crystal precursor and a monomer with an initiator or a cross-linkable oligomer or polymer with a cross-linking agent;   B) forming the slurry onto at least a surface of an anode current collector to form at least a reactive layer comprising the monomer with an initiator or the cross-linkable oligomer or polymer with a cross-linking agent; and   C) polymerizing the monomer or cross-linking the oligomer or polymer to form a high-elasticity polymer that embraces the primary particles of the anode active material and the conductive additive to form the active anode material layer.